Fuel cap with duck bill valve

ABSTRACT

A valve member provides for the flow of vapors from a fuel tank of an internal combustion engine to escape the fuel tank. The valve member may include a valve and a boss or spacer. The valve is configured to selectively control the flow of vapor from the fuel tank. The boss or spacer is positioned in a predetermined relationship to the valve, and the boss or spacer prevents a deformation of the valve from disrupting the selectively controlled flow of vapor from the fuel tank.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority benefit of Provisional Application No.62/592,962 filed Nov. 30, 2017, which is hereby incorporated byreference in its entirety.

FIELD

This disclosure relates in general to a fuel cap for an internalcombustion engine, and more specifically, to apparatus and techniquesfor regulation of evaporative emissions using the fuel cap.

BACKGROUND

A fuel tank for an internal combustion engine encloses and storescombustible fuel. The fuel may include hydrocarbons. The fuel naturallyevaporates into the atmosphere. When hydrocarbons evaporate and escapeto the atmosphere, the hydrocarbons may become pollutants. Evaporationrates may be increased by heat from warm weather. Evaporation levels mayaccumulate over time for engines that often spend long periods of timebetween starts and/or spend long periods in non-climate controlledenvironments such as garages. Evaporation is also caused from heat fromthe operation of the engine.

A fuel cap may vent pressurized fuel vapor out of the fuel tank into oneor more filters for removing hydrocarbons. High pressure in the fueltank may affect the venting of the pressurized vapor. Challenges remainin venting of evaporative fuel vapors from the fuel tank.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments are described herein with reference to thefollowing drawings.

FIG. 1 illustrates a fuel cap.

FIG. 2A illustrates an example exploded view of the fuel cap of FIG. 1.

FIG. 2B illustrates another example exploded view of the fuel cap ofFIG. 1.

FIG. 3 illustrates a cross sectional view of the fuel cap of FIG. 1.

FIG. 4A illustrates a more detailed view of the fuel cap of FIG. 1including a duckbill valve.

FIG. 4B illustrates the duckbill valve of FIG. 4A.

FIGS. 5A and 5B illustrate views of the top of the duckbill valve.

FIGS. 5C and 5D illustrate views of the bottom of the duckbill valve.

FIG. 5E illustrates a cross sectional side view of the duckbill valve.

FIGS. 6A and 6B illustrate views of the top of the duckbill valve withoutwardly arranged bosses.

FIGS. 6C and 6D illustrate views of the bottom of the duckbill valvewith outwardly arranged bosses.

FIG. 6E illustrates a cross sectional side view of the duckbill valvewith outwardly arranged bosses.

FIGS. 7A and 7B illustrate views of the top of the duckbill valve withinwardly arranged bosses.

FIGS. 7C and 7D illustrate views of the bottom of the duckbill valvewith inwardly arranged bosses.

FIG. 7E illustrates a cross sectional side view of the duckbill valvewith inwardly arranged bosses.

FIGS. 8A and 8B illustrate views of the top of the duckbill valve withboth outwardly and inwardly arranged bosses.

FIGS. 8C and 8D illustrate views of the bottom of the duckbill valvewith both outwardly and inwardly arranged bosses.

FIG. 8E illustrates a cross sectional side view of the duckbill valvewith both outwardly and inwardly arranged bosses.

FIGS. 9A and 9B illustrate views of the top of the duckbill valve with alarge spacer ring.

FIGS. 9C and 9D illustrate views of the bottom of the duckbill valvewith the large spacer ring.

FIG. 9E illustrates a cross sectional side view of the duckbill valvewith the large spacer ring.

FIGS. 10A and 10B illustrate views of the top of the duckbill valve witha small spacer ring.

FIGS. 10C and 10D illustrate views of the bottom of the duckbill valvewith the small spacer ring.

FIG. 10E illustrates a cross sectional side view of the duckbill valvewith the small spacer ring.

FIGS. 11A and 11B illustrate views of the top of the duckbill valve withthe large and small spacer rings.

FIGS. 11C and 11D illustrate views of the bottom of the duckbill valvewith the large and small spacer rings.

FIG. 11E illustrates a cross sectional side view of the duckbill valvewith the large and small spacer rings.

FIG. 12 illustrates a flowchart for manufacturing the fuel cap.

DETAILED DESCRIPTION

FIG. 1 illustrates a fuel cap 100, which may include at least an outershell or cover 105, an internal sleeve 140, and a tether 150. Theinternal sleeve 140 may couple internal components of the fuel cap 100together. The internal sleeve 140 may include a threading or anothercoupling mechanism to secure the fuel cap 100 to a fuel port of anengine. The tether 150 includes an extended member, which may be formedof plastic and may be flexible or rigid, that connects the fuel cap 100to an anchor. The anchor is sized larger than the largest dimension ofthe fuel port of the engine to prevent the fuel cap 100 from becomingdetached from the engine at a distance greater than the length of theextended member.

The engine may be a small internal combustion engine applicable tochainsaws, lawn mowers, wood chippers, stump grinders, concrete trowels,mini excavators, concrete saws, portable saw mills, weed trimmers,all-terrain vehicles, wood splitters, pressure washers, garden tillers,tractors, plows, snow blowers, welding equipment, generators, and otherdevices. Often such small engine containing devices are used in closeproximity to a user (e.g., a human). It is desirable to reduce orminimize the amount of hydrocarbon evaporative emissions from thesetypes of devices. The fuel cap 100 includes an evaporative emissionreduction device for reducing the leakage or escape of emissions fromthe fuel tank of the engine.

FIG. 2A illustrates an exploded view of the fuel cap 105 of FIG. 1including the evaporative emission reduction device. In addition to thecomponents discussed with respect to FIG. 1, the fuel cap 105 a includesan upper filter retainer 110 a, a lower filter retainer 125 a, a duckbill valve 130, a valve support 135 a, and a seal 145 a. The upperfilter retainer 110 a and the lower filter retainer 125 a support anupper filter 115 a and a lower filter 120 a. Various materials such asmolded plastic may be used for the internal sleeve 140 a, the tether 150a, the upper filter retainer 110 a, the lower filter retainer 125 a, thevalve support 135 a, and the seal 145 a. Additional, different, or fewercomponents may be included. FIG. 2B illustrates an example exploded viewof the fuel cap of FIG. 1 using similar components that vary instructure from the example of FIG. 2A including a fuel cap 105 b, anupper filter retainer 110 b, a lower filter retainer 125 b, a duck billvalve 130, a valve support 135 b, an internal sleeve 140 b, and a seal145 b. The upper filter retainer 110 b and the lower filter retainer 125b support an upper filter 115 a, a middle filter 118, and a lower filter120 a.

FIG. 3 illustrates a cross sectional view of the fuel cap of FIG. 1.Between the upper filter 115 and the lower filter 120 may be ahydrocarbon filter 300 that removes hydrocarbon material from the vaporreleased from the fuel tank. The hydrocarbon filter may adsorbhydrocarbons from the vapor. The hydrocarbon filter 300 may includeadsorption capsules. Vapor entering the hydrocarbon filter may behydrocarbon evaporative emission and the flow leaving the hydrocarbonfilter may be considered scrubbed vapor or air. The scrubbed air may besafe for release into the atmosphere according to one or more guidelinesor regulations. The upper filter 115, the lower filter 120, or both maybe formed from a felt or another type of fabric. Example types of fabricinclude a compounding non-spinning fabric. The combination of the upperfilter 115 the lower filter 120 may be referred to as a dilayercompounding non-spinning fabric. In one example, three layers (e.g.,upper filter 115 a, middle filter 118, and lower filter 120 a) form atrilayer fabric.

FIG. 4A illustrates a more detailed view of the fuel cap of FIG. 1including a duckbill valve 130. FIG. 4B illustrates the duckbill valve130 of FIG. 4A. The duck bill valve 130 may include multiple valves. Thevalves may include one or more one-way valve and/or one or more checkvalve. The valves allow air flow or pressure to flow in one directionthrough the duckbill valve 130 and not in another direction through theduckbill valve 130.

FIGS. 5A and 5B illustrate views of the top of a duckbill valve member530 including a major valve 533 and multiple minor valves (e.g., minorvalve 531 and 532). The major valve 533 may allow air flow in a firstdirection (e.g., into the fuel tank from the atmosphere or elsewhere inthe vicinity of the engine) and the minor valves 531 and 532 may allowair flow in a second direction (e.g., out of the fuel tank to theatmosphere or elsewhere in the vicinity of the engine). The valves mayhave any size, orientation, and direction. The terms minor and major donot necessarily represent relative size or flow volumes for the valves.

FIGS. 5C and 5D illustrate views of the bottom of the duckbill valvemember 530 and FIG. 5E illustrates a cross sectional side view of theduckbill valve, illustrating that the major valve 533 extends in a duckbill shape or a triangular prism shape away from the base of theduckbill valve member 530 towards the interior of the fuel tank. Themajor valve 533 includes a first angled portion 538 and a second angledportion 539 that terminate at opening 535. The minor valves 531 and 532each include a domed shaped cavity for openings 536 and 537,respectively, that is concave in a direction opposite that of theextension of the major valve 533. Thus, the major valve 533 and theminor valves 531 and 532 operate as one-way or check valves in oppositedirections.

When air or vapor pressure inside the fuel tank of the engine exceeds athreshold, a force is applied to the domed shaped cavities for openings536 and 537. The force causes the openings 537 and 537 to allow air orvapor flow from the fuel tank and into the fuel cap including theemission filter. When the pressure inside the fuel tank of the engineexceeds a second threshold, the force may cause the duckbill valvemember 530 to deform or otherwise change shape. Some of the deformationallows the duckbill valve member 530 to operate properly. However, whenthe duckbill valve member 530 becomes too deformed it may contact anadjacent member (e.g., lower filter retainer 125). Contact with theadjacent member may disrupt the valve operation and restrict the flow ofair out of the fuel tank.

FIG. 4B illustration a distance α between the adjacent member (e.g.,lower filter retainer 125) and the duckbill valve member 530. When thedistance α falls below a spacing threshold because the duckbill valvemember 530 has become too deformed, the duckbill valve member 530 doesnot operate properly.

The following embodiments include apparatus and techniques forpreventing this disruption of the valve operation and/or maintaining atleast the distance α between the adjacent member (e.g., lower filterretainer 125) and the duckbill valve member.

FIGS. 6A and 6B illustrate views of the top of the duckbill valve member630 with outwardly arranged bosses 690 and 691. FIGS. 6C and 6Dillustrate views of the bottom of the duckbill valve 630 with outwardlyarranged bosses 690 and 691. FIG. 6E illustrates a cross sectional sideview of the duckbill valve 630 with outwardly arranged bosses 690 and691.

The bosses 690 and 691 press against or near the adjacent member (e.g.,lower filter retainer 125). The bosses 690 and 691 prevent or reducedeformation to the duckbill valve member 630. Therefore, the duckbillvalve member 630 can operate under higher pressures in the fuel tankwithout reduction of the flow of air through the minor valves 531 and532.

The bosses 690 and 691 may be made of the same material as the duckbillvalve member 630 (e.g., rubber, elastomer, silicone orhydrocarbon-resistant fluorosilicone rubber). The bosses 690 and 691 maybe positioned at a predetermined distance (e.g., 1 mm) from minor valves531 and 532 in a direction of the circumference of the duckbill valvemember 630. The bosses 690 and 691 may be formed integrally with theduckbill valve member 630. In one example, the bosses 690 and 691 may bedimples pressed into the duckbill valve member 630 from the oppositeside.

Some arrangements may include different numbers of bosses (e.g., one,three, five, or another number). The bosses may be spaced at differentdistances from the major valve 533 or minor valves 531 and 531. Thebosses may be spaced from the circumference of the duckbill valve member630. The bosses may be another shape such as circular, triangular, oroval. The sides of the spacer rings may be sloped. The bosses may bearranged in a line in a direction perpendicular to a face of the bosses.Alternatively, the bosses may be arranged at different angles withrespect to the major valve 533, minor valves 531 and 531, or thecircumference of the duckbill valve member 630. The bosses 690 and 691,or other bosses described herein, may be sized at 1 mm cubed, 1 mm by 2mm by 1 mm, or another size. One of the bosses may be one size andanother of the bosses may be a different size. Any of these variationsmay be applied to bosses 690 and 691 as well as other embodimentsherein.

FIGS. 7A and 7B illustrate views of the top of the duckbill valve 730with inwardly arranged bosses 790 and 791. FIGS. 7C and 7D illustrateviews of the bottom of the duckbill valve 730 with inwardly arrangedbosses 790 and 791. FIG. 7E illustrates a cross sectional side view ofthe duckbill valve 730 with inwardly arranged bosses 790 and 791.

The bosses 790 and 791 press against or near the adjacent member (e.g.,lower filter retainer 125). The bosses 790 and 791 prevent or reducedeformation to the duckbill valve member 730. Therefore, the duckbillvalve member 730 can operate under higher pressures in the fuel tankwithout reduction of the flow of air through the minor valves 531 and532.

The bosses 790 and 791 may be made of the same material as the duckbillvalve member 730 (e.g., rubber, elastomer, silicone orhydrocarbon-resistant fluorosilicone rubber). The bosses 790 and 791 maybe positioned at a predetermined distance (e.g., 1 mm) from minor valves531 and 532 in a direction toward the center of the duckbill valvemember 630. The bosses 790 and 791 may be positioned at a predetermineddistance (e.g., 0.1 mm) from major valve 533 in a direction toward thecircumference of the duckbill valve member 630. Variations in shapes,sizes, quantity, and arrangement of bosses 790 and 791 may be made andexamples of such variations are described in other embodiments herein.

FIGS. 8A and 8B illustrate views of the top of the duckbill valve 830with both outwardly arranged bosses 690 and 691 and inwardly arrangedbosses 790 and 791. FIGS. 8C and 8D illustrate views of the bottom ofthe duckbill valve 830 with outwardly arranged bosses 690 and 691 andinwardly arranged bosses 790 and 791. FIG. 8E illustrates a crosssectional side view of the duckbill valve 830 with both outwardlyarranged bosses 690 and 691 and inwardly arranged bosses 790 and 791.Variations in shapes, sizes, quantity, and arrangement of bosses 690,691, 790 and 791 may be made and examples of such variations aredescribed in other embodiments herein.

FIGS. 9A and 9B illustrate views of the top of the duckbill valve 930with a large spacer ring 990. FIGS. 9C and 9D illustrate views of thebottom of the duckbill valve 930 with the large spacer ring 990. FIG. 9Eillustrates a cross sectional side view of the duckbill valve 930 withthe large spacer ring 990. The large spacer ring 990 may have a diametergreater than a width of the major valve 533 and smaller than a dimeterof the duckbill valve 930. Examples for the diameter of the large spacerring 990 may include 10 mm and 15 mm.

FIGS. 10A and 10B illustrate views of the top of the duckbill valve 1030with a small spacer ring 1090. FIGS. 10C and 10D illustrate views of thebottom of the duckbill valve 1030 with the small spacer ring 1090. FIG.10E illustrates a cross sectional side view of the duckbill valve 1030with the small spacer ring 1090. The small spacer ring 1090 may have adiameter smaller than a width of the major valve 533. The small spacerring 1090 may have a diameter equal to or greater than a width of theminor valves 531 and 532. Examples for the small spacer ring 1090 mayinclude 5 mm and 8 mm.

FIGS. 11A and 11B illustrate views of the top of the duckbill valve 1130with the large spacer ring 990 and the small spacer ring 1090. FIGS. 11Cand 11D illustrate views of the bottom of the duckbill valve 1130 withthe large spacer ring 990 and the small spacer ring 1090. FIG. 11Eillustrates a cross sectional side view of the duckbill valve 1130 withthe large spacer ring 990 and the small spacer ring 1090. A ratiobetween the diameter of the large spacer ring 990 and the small spacerring 1090 may be in a range from 1.5 to 3. An example ratio is 2 suchthat the large spacer ring 990 is twice the width of the small spacerring 1090.

Examples for the width and height (H) of the large spacer ring 990 andthe small spacer ring 1090 may include 1 mm, 1.2 mm, 1.5 mm, and 2 mm.The spacer rings may have the same or different width or heights. Thespacer rings may not be complete rings. In some examples, one or more ofthe spacer rings may be semi-circles or quarter-circles. The spacerrings may be another proportion of a complete circle such as 70% or 90%.The spacer rings may be discontinuous and formed of spaced portions(e.g., dashed circle shape). Other quantities of spacer rings may beused. The spacer rings may be concentric or arranged at different sidesof the duckbill valve member. The spacer rings, rather than circular,may be square, rectangular or another shape. The sides of the spacerrings may be sloped.

FIG. 12 illustrates an example flowchart for manufacturing a fuel capincluding a duckbill filter or valve and an evaporative emissionreduction device. Additional, different, or fewer acts may be included.

An act S101, an evaporative emission reduction device is provided to afuel cap (e.g., fuel cap 100). The evaporative emission reduction devicemay include a hydrocarbon filter that adsorbs vapor or hydrocarbonmaterial from the vapor released from the fuel tank. The evaporativeemission reduction device reduces the escape of vapors from a fuel tank.

At act S103, a deformation prevention member is mounted on a valvemember. The deformation prevention member may include one component, twocomponents, or more than two components. The deformation preventionmember may include at least one dimension (e.g., height) that meets orexceeds a deformation prevention threshold distance. The deformationprevention threshold distance may be selected according to thedimensions or materials of the valve member. Stiffer (e.g., withcoefficient of elasticity below a predetermined value) valve members mayhave lower deformation prevention thresholds and require larger heightfor the deformation prevention member. More flexible (e.g., withcoefficient of elasticity above a predetermined value) valve members mayhave higher deformation prevention thresholds and require smaller heightfor the deformation prevention member.

The deformation prevention member prevents the valve from becomedeformed, which may affect the control of the escape of vapors from thefuel tank. The valve member may be shaped in a disc that can twist orbecome contorted and prevent the valve opening from opening and closingin normal operation. The deformation may be caused by pressure above apredetermined pressure threshold in the fuel tank. The pressurethreshold may depend on the size of the fuel tank, the shape of the fueltank, the type of fuel in the fuel tank, the diameter of the fuel tankopening for the fuel tank, and/or the width and materials for the valvemember. The deformation prevention member may be placed at apredetermined distance from the opening of the valve to protect theshape of the valve member and ensure that the valve opening open andcloses in normal operation.

The deformation prevention member may be placed between the valve and anouter circumference of the valve member or between the valve in and acenter of the valve member. The deformation prevention member mayinclude two components include a first ring outside of the valve in adirection of an outer circumference of the valve member and a secondring that overlaps the valve.

At act S105, the valve member is aligned to the evaporative emissionreduction device with a valve retainer. The valve retainer may includemultiple layers such as the upper filter retainer 110 a and the lowerfilter retainer 125 a.

At act S107, the deformation prevention member, the valve retainer, andthe evaporative emission reduction device are secured to the fuel capwith a retainer sleeve. The retainer sleeve may include an outer shellor cover 105, an internal sleeve 140, or a combination of shell 105 andinternal sleeve 140.

In one implementation, the fuel cap may be anchored to the fuel cap orthe engine including the fuel tank with a tether (e.g., tether 150). Thetether may be shaped so that it cannot be removed from the fuel tankthrough the opening for the fuel tank. In another example, the tether isa cable or other coupling device that is secured to the fuel tank or theengine by a bolt, welding, rivet, or another fastening technique.

The illustrations of the embodiments described herein are intended toprovide a general understanding of the structure of the variousembodiments. The illustrations are not intended to serve as a completedescription of all of the elements and features of apparatus and systemsthat utilize the structures or methods described herein. Many otherembodiments may be apparent to those skilled in the art upon reviewingthe disclosure. Other embodiments may be utilized and derived from thedisclosure, such that structural and logical substitutions and changesmay be made without departing from the scope of the disclosure.Additionally, the illustrations are merely representational and may notbe drawn to scale. Certain proportions within the illustrations may beexaggerated, while other proportions may be minimized. Accordingly, thedisclosure and the figures are to be regarded as illustrative ratherthan restrictive.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of the invention or of what may beclaimed, but rather as descriptions of features specific to particularembodiments of the invention. Certain features that are described inthis specification in the context of separate embodiments can also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable sub-combination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a sub-combination or variation of a sub-combination.

Similarly, while operations are depicted in the drawings and describedherein in a particular order, this should not be understood as requiringthat such operations be performed in the particular order shown or insequential order, or that all illustrated operations be performed, toachieve desirable results. In certain circumstances, multitasking andparallel processing may be advantageous. Moreover, the separation ofvarious system components in the embodiments described above should notbe understood as requiring such separation in all embodiments, and itshould be understood that the described program components and systemscan generally be integrated together in a single software product orpackaged into multiple software products.

One or more embodiments of the disclosure may be referred to herein,individually and/or collectively, by the term “invention” merely forconvenience and without intending to voluntarily limit the scope of thisapplication to any particular invention or inventive concept. Moreover,although specific embodiments have been illustrated and describedherein, it should be appreciated that any subsequent arrangementdesigned to achieve the same or similar purpose may be substituted forthe specific embodiments shown. This disclosure is intended to cover anyand all subsequent adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the description.

It is intended that the foregoing detailed description be regarded asillustrative rather than limiting and that it is understood that thefollowing claims including all equivalents are intended to define thescope of the invention. The claims should not be read as limited to thedescribed order or elements unless stated to that effect. Therefore, allembodiments that come within the scope and spirit of the followingclaims and equivalents thereto are claimed as the invention.

We claim:
 1. A valve member comprising: a first valve configured toselectively control a flow of vapor from a fuel tank; and a bosspositioned in a predetermined relationship to the first valve, whereinthe boss prevents a deformation of the first valve from disrupting theselectively controlled flow of vapor from the fuel tank, a second valveconfigured to selectively control a flow air into the fuel tank, whereinthe boss is a ring outside of a width of the second valve.
 2. The valvemember of claim 1, wherein the boss is spaced from the first valve in adirection of a circumference of the valve member.
 3. The valve member ofclaim 1, wherein the boss is spaced from the first valve in a directionof the center of the valve member.
 4. The valve member of claim 1,wherein the boss is a ring inside of a width of the second valve.
 5. Thefuel cap of claim 1, wherein the valve, if deformed, disrupts theselectively controlled escape of vapor from the fuel tank.
 6. The fuelcap of claim 1, further comprising: a tether configured to anchor thefuel cap to the fuel tank or an engine including the fuel tank.
 7. Afuel cap comprising: an evaporative emission reduction device configuredto reduce escape of vapors from a fuel tank; a valve configured toselectively control the escape of vapors from the fuel tank; a spacerpositioned in a predetermined relationship to the valve, wherein thespacer prevents deformation in the valve; and a valve retainerconfigured to support the valve and align the valve with the evaporativeemission reduction device.
 8. The fuel cap of claim 7, furthercomprising: a valve member shaped in a disc and comprising the valve. 9.The fuel cap of claim 8, wherein the spacer is between the valve and anouter circumference of the valve member.
 10. The fuel cap of claim 8,wherein the spacer is between an outer circumference of the valve memberand a center of the valve member.
 11. The fuel cap of claim 10, whereinthe spacer includes a first ring outside of the valve in a direction ofan outer circumference of the valve member.
 12. The fuel cap of claim11, wherein the spacer includes a second ring that overlaps the valve.13. The fuel cap of claim 8, wherein the valve is a first valve, and thevalve member includes a second valve configured to selectively control aflow air into the fuel tank.
 14. The fuel cap of claim 7, wherein theevaporative emission reduction device is an adsorption filter configuredto adsorb vapors from the fuel tank.
 15. A method of manufacturing afuel cap including an evaporative emission reduction device and a valve,the method comprising: providing an evaporative emission reductiondevice to a fuel cap; mounting a deformation prevention member on avalve member; aligning the valve member to the evaporative emissionreduction device with a valve retainer; and securing the deformationprevention member, the valve retainer, and the evaporative emissionreduction device to the fuel cap with a retainer sleeve.
 16. The methodof manufacturing the fuel cap of claim 15, further comprising: anchoringthe fuel cap to a fuel tank or an engine with a tether.
 17. The methodof manufacturing the fuel cap of claim 15, wherein mounting thedeformation prevention member on the valve member comprises: mounting afirst deformation prevention member on the valve member; and mounting afirst deformation prevention member on the valve member.